This invention relates to apparatus and methods for separating a stack of sheets into bundles.
This invention is particularly applicable for use with interfolding of paper sheets in the formation of a stack of interfolded sheets; and the forming of discrete bundles, with each bundle having the same number of sheets.
The interfolding of sheets is well known. U.S. Pat. No. 2,761,677 Rutkus et al. teaches a rotary interfolder, for forming a stack of interfolded sheets. Similarly U.S. Pat. No. 4,190,241 to Krueger teaches another apparatus for forming a stack of interfolded sheets. In the Rutkus patent the stack of sheets is fed to an elongated chute accumulator. The stack is eventually fed to a stack separating mechanism displaced some distance from the stack forming area which stack forming area is at the discharge of the interfolding apparatus. The Krueger patent teaches the use of an elevator to remove an exact number of C-folded sheets. While the elevator is removing the stack, an accumulator plate continues to accumulate additional sheets until the elevator returns. U.S. Pat. No. 2,675,747 Greiner et al. teaches a vertically moving accumulator elevator. A cutting separator plate and pusher combination cuts the sheet bonds and pushes the bundle sideways off the elevator. U.S. Pat. No. 4,508,527 to Uno et al. teaches another method of separating folded sheets of paper into individual bundles.